Solid-state imaging device and signal processing circuit

Abstract

A solid-state imaging device includes a semiconductor substrate having a principal surface, and three or more pixel regions formed in at least one direction of two different directions along the principal surface of the semiconductor substrate. Each pixel region includes a plurality of photoelectric conversion regions having different sensitivities. The photoelectric conversion region having the highest sensitivity in peripheral pixel regions of the pixel regions has a higher sensitivity than the photoelectric conversion region having the highest sensitivity in a central pixel region of the pixel regions.

What is claimed is: 
     
       1. A solid-state imaging device comprising:
 a semiconductor substrate having a surface; 
 three or more pixel regions formed in at least one direction of two different directions along the principal surface of the semiconductor substrate, the three or more pixel regions comprising a central pixel region and peripheral pixel regions around the central pixel region, each pixel region including a plurality of photoelectric conversion regions having different sensitivities, 
 wherein the photoelectric conversion region having the highest sensitivity in the peripheral pixel regions has a higher sensitivity than the photoelectric conversion region having the highest sensitivity in the central pixel region; and 
 a signal processing circuit configured to process a signal that is photoelectrically converted by the pixel regions, the signal processing circuit being included in or being external to the solid-state imaging device, 
 wherein the signal processing circuit corrects for gains of the central pixel region and the peripheral pixel regions in accordance with an f value and corrects for shading that is caused in a region other than the photoelectric conversion regions having the highest sensitivity in the pixel regions, and 
 the signal processing circuit includes:
 a multiplying circuit that multiplies a signal output from the region other than the photoelectric conversion regions having the highest sensitivity in the pixel regions or a signal obtained by performing signal processing on the output signal by a coefficient that is determined for each of the pixel regions; and 
 an adding circuit that adds the signal output from the region other than the photoelectric conversion regions having the highest sensitivity in the pixel regions or the signal obtained by performing signal processing on the output signal to the signal multiplied by the coefficient. 
 
 
     
     
       2. The solid-state imaging device according to  claim 1 , wherein the signal processing circuit further includes an analog-to-digital converter circuit configured to perform analog-to-digital conversion on the signal. 
     
     
       3. The solid-state imaging device according to  claim 2 , wherein the signal processing circuit further includes a memory configured to temporarily store an output of the analog-to-digital converter. 
     
     
       4. The solid-state imaging device according to  claim 1 , wherein the signal processing circuit further includes a memory configured to temporarily store an output of the multiplying circuit. 
     
     
       5. A signal processing circuit for processing a signal that is photoelectrically converted by a plurality of pixel regions of a solid-state imaging device, the plurality of pixel regions comprising a central pixel region and peripheral pixel regions around the central pixel region, the signal processing circuit being included in or being external to the solid-state imaging device, said signal processing circuit comprising a circuit that corrects for gains of the central pixel region and the peripheral pixel regions in accordance with an f value, the signal processing circuit further comprising:
 an amplifying circuit that multiplies a signal output from a region other than a photoelectric conversion region having the highest sensitivity in the pixel regions or a signal obtained by performing signal processing on the output signal by a coefficient that is determined for each of the pixel regions; and 
 an adding circuit that adds the signal output from the region other than the photoelectric conversion region having the highest sensitivity in the pixel regions or the signal obtained by performing signal processing on the output signal to the signal multiplied by the coefficient. 
 
     
     
       6. The signal processing circuit according to  claim 5 , further comprising an analog-to-digital converter circuit configured to perform analog-to-digital conversion on the signal. 
     
     
       7. The signal processing circuit according to  claim 6 , further comprising a memory configured to temporarily store an output of the analog-to-digital converter. 
     
     
       8. The signal processing circuit according to  claim 5 , further comprising a memory configured to temporarily store an output of the multiplying circuit. 
     
     
       9. A solid-state imaging device comprising:
 a pixel region having a high-sensitivity photoelectric conversion region and a low-sensitivity photoelectric conversion region; 
 a lens; and 
 a signal processing circuit configured to process a signal output of the pixel region, 
 wherein the signal processing circuit is configured to correct for gains of the pixel region in accordance with an f value of the lens and to correct for shading in the low-sensitivity photoelectric conversion region, and 
 the signal processing circuit includes:
 an amplifying circuit configured to multiply a signal output from the low-sensitivity photoelectric conversion region or a signal obtained by performing signal processing on the output signal by a coefficient that is determined for each of the high-sensitivity and low-sensitivity photoelectric conversion regions; and 
 an adding circuit that adds the signal output from the low-sensitivity photoelectric conversion region or the signal obtained by performing signal processing on the output signal to the signal multiplied by the coefficient. 
 
 
     
     
       10. The solid-state imaging device according to  claim 9 , wherein the signal processing circuit further includes an analog-to-digital converter circuit configured to perform analog-to-digital conversion on the signal. 
     
     
       11. The solid-state imaging device according to  claim 10 , wherein the signal processing circuit further includes a memory configured to temporarily store an output of the analog-to-digital converter. 
     
     
       12. The solid-state imaging device according to  claim 9 , wherein the signal processing circuit further includes a memory configured to temporarily store an output of the multiplying circuit.